Implantable medical devices including septum-based indicators

ABSTRACT

A method of making an access port, includes providing a port body defining a fluid cavity, positioning a septum over the fluid cavity, and securing the septum to the port body. The septum includes a lower portion having a first diameter, an upper portion joined to the lower portion at a juncture, the upper portion having a second diameter less than the first diameter at the juncture, and a plurality of palpation features joined to the upper portion. Each of the palpation features includes a first end adjacent a central axis of the septum, and a second end extending radially outward, overlapping the juncture.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/105,774, filed Aug. 20, 2018, now U.S. Pat. No. 10,773,066, which isa division of U.S. patent application Ser. No. 14/587,862, filed on Dec.31, 2014, now U.S. Pat. No. 10,052,471, which is a division of U.S.patent application Ser. No. 12/617,981, filed Nov. 13, 2009, now U.S.Pat. No. 8,932,271, which claims the benefit of U.S. Provisional PatentApplication No. 61/114,331, filed Nov. 13, 2008, and titled“Septum-Based Indicators for an Implantable Medical Device,” each ofwhich is incorporated herein by reference in its entirety.

BRIEF SUMMARY

Briefly summarized, embodiments of the present invention are directed toa medical device, such as an access port for providing subcutaneousaccess to a patient. The access port includes a septum includingpalpable identification indicia thereon. In particular, the access portin one embodiment includes a body that defines a fluid cavity and aneedle-penetrable septum covering the fluid cavity for providing accessthereto. The septum defines an outer periphery.

The palpable identification indicia of the septum are included as aplurality of raised palpation features. Each palpation feature includesa portion that extends in a radial direction beyond the outer peripheryof the septum. The palpation features are therefore disposed relativelyfarther away from each other, simplifying palpation and identificationthereof after the port has been subcutaneously implanted into a patient.The palpation features can be indicative of an attribute of the port,such as its ability to withstand fluid pressures and flow ratesassociated with power injection, for instance.

In other embodiments, the size, shape, number, and placement of thepalpation features on the septum or other port surface can vary asappreciated by those skilled in the art.

These and other features of embodiments of the present invention willbecome more fully apparent from the following description and appendedclaims, or may be learned by the practice of embodiments of theinvention as set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

A more particular description of the present disclosure will be renderedby reference to specific embodiments thereof that are illustrated in theappended drawings. It is appreciated that these drawings depict onlytypical embodiments of the invention and are therefore not to beconsidered limiting of its scope. Example embodiments of the inventionwill be described and explained with additional specificity and detailthrough the use of the accompanying drawings in which:

FIG. 1A is a perspective view of an implantable port including a septumconfigured according to one example embodiment;

FIG. 1B is a top view of the port of FIG. 1A;

FIG. 2 is a cross sectional view of the port of FIG. 1B, taken along theline 2-2;

FIG. 3 is a perspective view of the septum included in the port of FIG.1A;

FIG. 4 is a cross sectional view of the septum of FIG. 3 , taken alongthe line 4-4;

FIG. 5 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 6 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 7 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 8 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 9 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 10 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 11 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 12 is a top view of an implantable port including a septumconfigured according to one embodiment;

FIG. 13 is an exploded perspective view of an implantable port includinga septum configured according to one embodiment;

FIG. 14 is a top view of an implantable port configured according to oneembodiment; and

FIGS. 15A and 15B are a top and side view, respectively, of animplantable port configured according to one embodiment.

DETAILED DESCRIPTION OF SELECTED EMBODIMENTS

Reference will now be made to figures wherein like structures will beprovided with like reference designations. It is understood that thedrawings are diagrammatic and schematic representations of exemplaryembodiments of the present invention, and are neither limiting nornecessarily drawn to scale.

FIGS. 1A-15B depict various features of embodiments of the presentinvention, which are generally directed to medical devices includingports, also referred to herein as access ports, for implantation intothe body of a patient. In some situations, it can be desirable tofacilitate access to the vasculature of a patient for purposes of bloodwithdrawal and/or infusions, such as when the patient is ill and mayrepeatedly undergo such procedures. In one implementation, vascularaccess is established via a catheter situated within a blood vessel ofthe patient. A port, subcutaneously implanted in the patient, is placedin fluid communication with the catheter. Accordingly, infusions andblood withdrawals may be made percutaneously via the port, rather thandirectly through the wall of a blood vessel.

Reference is first made to FIGS. 1A-4 , wherein an implantable port 10is disclosed as configured in accordance with one example embodiment. Asshown, the port 10 includes a body, or housing 20, which defines a fluidcavity 30 in communication with a rimmed opening, or aperture 34, on anupper surface of the port. The housing 20 defines a passageway 40 influid communication with the fluid cavity 30 into which a stem 31 isdisposed, wherein the stem is configured for coupling with a lumen of acatheter so as to provide fluid communication between the catheter andthe fluid cavity. In another embodiment, the stem can be integrallyformed with the housing.

In the present embodiment, the port 10 includes a septum 50. The septum50 is coupled with the housing 20 to cover the aperture 34 and the fluidcavity 30 defined by the housing, thus providing selective access to thefluid cavity. In the present embodiment, for example, the septum 50includes an elastomeric material capable of being punctured by a needle,for example, a Huber needle, and substantially resealing upon removal ofthe needle. In one embodiment, the septum 50 includes silicone, thoughother materials can also be employed. In the illustrated embodiment, theport housing 20 includes a metallic material such as stainless steel ortitanium, and the septum 50 is secured in place in the housing by ametallic retaining ring 24 that is press fit into the housing, as shownin FIG. 2 . As will be seen below, the principles of the presentdisclosure can be employed with other port materials and configurations.These and other configurations are therefore contemplated.

The port 10 is configured to be implanted subcutaneously within apatient and operably connected to a catheter that, in turn, is disposedwithin a vein or other vessel. Accordingly, when the catheter is coupledwith the stem 31 of the port 10, fluid communication can be establishedwith the vessel via the fluid cavity 30, such as by an infusion needleinserted through the septum 50 of the port. A plurality of suture holes42 can be included in the housing 20 so as to facilitate securement ofthe port 10 to the tissue of the patient when implanted.

The septum 50 in the present embodiment is defined by a body 52including an upper body portion 52A that is generally exposed throughthe aperture 34 of the port 10 and a lower body portion 52B that isgenerally included within the interior of the port housing 20. The upperbody portion 52A and lower body portion 52B define a juncture 53. Theupper body portion 52A includes a top surface 56 and an outer periphery54. Though the present embodiments deal particularly with the outerperiphery 54, i.e., a first outer periphery of the septum upper bodyportion 52A, the lower body portion 52B can be considered to define asecond outer periphery including a relatively larger diameter than thatof the first outer periphery.

In the present embodiment the periphery 54 of the upper body portion 52Aof the septum 50 is circular to match the circular aperture 34, but inother embodiments it is appreciated that the outer periphery of theseptum could define other shapes, including triangular, square,polygonal, other geometric shapes, etc. To the extent that the peripheryof the septum defines other shapes, in some embodiments the shape of theaperture can also be modified to correspond in shape to that of theseptum.

According to the present embodiment, a plurality of palpation featuresis included on the septum 50. As shown in FIGS. 1A-4 , the palpationfeatures are included as three protrusions 60 that extend from a surfaceof the septum 50. The three protrusions 60 are equidistantly spaced atsubstantially regular intervals around an outer portion of the septum 50as to define end points, or vertices, of an imaginary triangle such asan equilateral triangle in the present embodiment. As best seen in FIG.1B, the protrusions 60 generally align with the vertices of thegenerally triangularly-shaped port housing 20. The protrusions 60 extendupward from the generally flat septum top surface 56 such that theprotrusions provide surface features to a top profile of the port 10from the perspective shown in FIG. 2 .

Note that, though three are used here, fewer or more palpableprotrusions can be included on the septum top surface. Indeed, only oneprotrusion can be employed if desired. Also, though the port shown hereis a port with a singular fluid cavity, multi-lumen ports including aplurality of fluid cavities and corresponding septa can include thepalpation features discussed herein. The spacing, shape, and size of thepalpation features can vary in a number of ways, some of which aredescribed further below.

As best seen in FIG. 1B, the protrusions 60 are shaped and positioned asto include a radially outward portion 62 that radially extends past thecircular outer periphery 54 of the septum 50. Thus, the radially outwardportion 62 of each protrusion 60 extends beyond, or overlaps, theaperture 34 and thus extends over a portion of the retaining ring 24.The radially outward portion 62 of each protrusion 60 includes a bottomsurface 55 extending angularly away from the upper body portion 52A ofthe septum 50, as shown in FIG. 4 .

The overlapping aspect of the protrusions 60 causes a center point ofeach protrusion to be disposed relatively farther away from the otherprotrusions than if the protrusions were confined within the boundsdefined by the septum outer periphery 54. This in turn enables theprotrusions to be more easily palpated and identified by a clinicianperforming the palpation for an implanted port than if the protrusionswere closer set. Thus, the tactile acuity of the clinician palpating theport 10 is preserved without increasing the size of either the septum orits protrusions. Desire for increased tactile acuity has increased inrecent years in light of the trend toward a reduction in size ofmanufactured ports, and by extension, septum size.

In greater detail, FIG. 4 shows one of the protrusions 60 of the septum50 in cross section, wherein a notch 64 is defined by virtue of theoverlapping nature of the protrusion. The notch 64 enables theprotrusion to extend over the edge of the aperture 34, defined in thisembodiment by the retaining ring 24, without interfering with theretaining ring. Of course, the size and shape of the notch andprotrusion can be modified to adapt to a particular port configuration.

The protrusions 60 in the present embodiment are oblong-shaped,generally resembling a seed or tear drop shape, and include a smoothlycontoured surface, as best seen in FIGS. 1B and 3 . The smooth contourof the protrusions 60 assists in reducing tissue irritation when theport 10 is implanted in the patient. In the present embodiment where theseptum 50 generally defines a disc-like shape including an outerperiphery diameter of about 0.42 inch (indicated at X₁ on FIG. 4 ), theprotrusions 60 axially extend a distance of about 0.046 inch above thetop surface 56 of the septum body 52 (indicated at Y on FIG. 4 ) andabout 0.055 inch radially beyond the periphery 54 (indicated at X₂ onFIG. 4 ), though other size dimensions are of course possible. Theprotrusions 60 are integrally formed with the septum 50 in the presentembodiment, but could be separately formed and attached to the septum inanother embodiment. Note that the shapes of the protrusions can beshaped in other ways, as will be seen further below. Note further thateach protrusion on the septum can include a different shape with respectto the other protrusions, if desired.

In one embodiment, the palpation features, i.e., protrusions 60 of theseptum 50, can permit a clinician to properly identify a predeterminedattribute or characteristic of the port 10. The attribute of the port 10in one embodiment is the suitability of the port to withstand relativelyhigh fluid flow and/or fluid pressure rates therethrough, commonlyreferred to as “power injection.” Such high pressure and flow rates aretypically associated with power injection of fluids through the portduring relatively demanding procedures (e.g., computed tomography, or“CT,” scans), in which contrast media is rapidly infused through theport and connected catheter and into a vascular system. For instance, inone embodiment power injection includes fluid infusion by a powerinjection machine producing fluid pressures of up to about 325 psi,resulting in fluid pressures in the port 10 between about 50 and about90 psi and fluid flow through the port at a rate between about two andabout five milliliters per second. Other flow rates and fluid pressuresare, of course, possible.

During power injection, a needle can be inserted in a septum of the portand connected to a power injection machine, which can introduce contrastmedia through the port at a relatively high flow rate, as detailedabove. Certain ports may not be able to withstand pressurescorresponding to high flow rates during power injection. Accordingly, itis often necessary to determine whether an implanted port is compatiblefor power injection.

The protrusions 60 enable identification of a port as power injectable,in one embodiment. In particular, after subcutaneous implantation of theport 10 in a patient, a clinician cannot visually observe the port todetermine whether it is suitable for power injection. With a port 10configured as shown in FIGS. 1A-4 , the clinician can feel or palpatethe three protrusions 60 through the skin to determine that the port issuitable for power injection. In addition, other information regardingthe port 10 can be gathered by palpation, including the generalorientation of the port, location the septum 50, etc.

In addition to its suitability for power injection, in other embodimentsother predetermined attributes or characteristics of the port can beindicated by the protrusions described herein. Such attributes include,for example, the type of catheter to which the port is connected, e.g.,whether the catheter distal tip is open-ended or includes distal valve,the type of material from which the port is constructed, etc. Suchability to determine the predetermined characteristic(s) of the port isuseful for ports of all types, including those made fromradio-translucent materials, which are not sufficiently imagedradiographically.

As already described, the protrusions 60 in FIGS. 1A-4 are teardrop-shaped to provide a smooth contour surface and to avoid irritatingbody tissue proximate the port implanted location. In other embodiments,though, the shape, size, number, and placement of the palpation featurescan be modified from what is explicitly shown and described herein inorder to suit a particular need. FIGS. 5-12 give several examples ofdifferent possible protrusion configurations for the septum 50 of theport 10. FIG. 5 shows overlapping protrusions 160 defining a flatcylindrical shape. FIG. 6 depicts protrusions 260 defining flatcylindrical shapes similar to those shown in FIG. 5 , wherein theprotrusions 260 overlap the aperture 34 a relatively more than theprotrusions 160 of FIG. 5 .

FIGS. 7 and 8 depict protrusions 360 and 460 that define oblong androughly conical shapes, respectively, while FIGS. 9 and 10 respectivelydepict semi-spherical protrusions 560 and 660. FIGS. 11 and 12 showrelatively thin protrusions 760 and 860 disposed with their long axesextending tangentially to the septum outer periphery 54. Note that theouter periphery 54 of the septum 50 in FIG. 12 generally defines atriangular shape.

As described above, the principles of the present disclosure can beapplied to ports from a variety of materials. FIG. 13 gives one exampleof this, wherein a port 1010 is shown including a cap 1014 and a base1016, both formed from an engineering plastic material, such asPolyoxymethylene (“POM”), also known as an acetal resin, or othersuitable material. The septum 50 including the protrusions 60 issandwiched between the cap 1014 and base 1016 so as to be capturedtherebetween when the cap and base are mated together and such that theprotrusions overlap past an aperture 1034 defined by the cap 1014. Notethat in the illustrated embodiment, four overlapping protrusions areincluded on the septum 50, in contrast to embodiments described earlier.Suture plugs 1022 and a stem 1031 are also included with the port 1010.

Palpation features can be included on the port in other configurations,as shown in FIGS. 14-15B. In FIG. 14 , a plurality of protrusions 962 isincluded on the housing 20 of the port 10. The protrusions 962 can behard or resilient and are spaced so as to enable palpation of the port10 when subcutaneously implanted. The protrusions 962 can be adhered tothe port housing surface 20 via an adhesive, can be inserted intocorresponding holes defined in the housing, or can be included in othersuitable ways. Note that, as before, the size, shape, number, andconfiguration of the protrusions can vary from what is explicitly shownhere.

FIGS. 15A and 15B show a plurality of protrusions 1062 inserted into thesuture holes 42 of the port housing 20. The protrusions 1062 areresilient and extend a predetermined distance above a top surface of theport 10 so as to enable palpation thereof when the port is implanted.The protrusions 1062 are inserted and secured in the suture holes 42 viaa friction fit, mechanical capture, or other suitable method. Of course,the number, size, position, and shape of both the suture holes andcorresponding protrusions can vary from what is explicitly describedherein.

The number, size, position, and shape of the palpation features can bemodified while residing within the scope of embodiments of the presentinvention. In addition to the above embodiments, it is appreciated, forexample, that the protrusions can define patterns other than equilateraltriangles, including acute triangles, obtuse triangles, squares, etc.Additionally, one, two, three, four, five, or more protrusions could beused. In one embodiment, the port includes two or more septa withprotrusions extending from each. The protrusions can define a variety ofdifferent shapes, and may be sized differently. Indeed, the protrusionscan include configurations such as those shown and described in U.S.Pat. No. 8,177,762, which is incorporated herein by reference in itsentirety. Thus, the foregoing examples are merely illustrative innature.

Embodiments of the invention may be embodied in other specific formswithout departing from the spirit of the present disclosure. Thedescribed embodiments are to be considered in all respects only asillustrative, not restrictive. The scope of the embodiments is,therefore, indicated by the appended claims rather than by the foregoingdescription. All changes that come within the meaning and range ofequivalency of the claims are to be embraced within their scope.

What is claimed is:
 1. A septum providing access to a fluid cavity of asubcutaneously implanted access port, the septum comprising: a lowerportion having a first diameter; an upper portion joined to the lowerportion at a juncture, the upper portion having a second diameter lessthan the first diameter at the juncture; and a plurality of palpationfeatures joined to the upper portion, each of the plurality of palpationfeatures including: a first end adjacent a central axis of the septum;and a second end extending radially outward to overlap the juncture, thesecond end including a bottom surface extending angularly away from theupper portion.
 2. The septum according to claim 1, wherein the pluralityof palpation features includes three equidistantly spaced protrusions.3. The septum according to claim 2, wherein each of the threeequidistantly spaced protrusions is tear-shaped.
 4. The septum accordingto claim 1, wherein the plurality of palpation features are designed toindicate an attribute of the subcutaneously implanted access port. 5.The septum according to claim 4, wherein the attribute of thesubcutaneously implanted access port is a capability to support fluidflow therethrough at a rate of at least five milliliters per second. 6.The septum according to claim 4, wherein the attribute of thesubcutaneously implanted access port is suitability for power injectionof a fluid through the access port.
 7. The septum according to claim 4,wherein the attribute of the subcutaneously implanted access port is amaterial from which the subcutaneously implanted access port is formed.8. The septum according to claim 1, wherein the plurality of palpationfeatures are designed to indicate an attribute of a catheter connectedto the subcutaneously implanted access port.
 9. The septum according toclaim 8, wherein the attribute of the catheter is whether a distal tipof the catheter is open-ended or valved.
 10. The septum according toclaim 1, wherein each of the plurality of palpation features have ashape selected from the group consisting of tear-shaped, triangular,semi-spherical, round, elongate, and oblong.